Common sense indicating not to buy one of these:

1. Ebay seller probably has one of these for sale for every vehicle from a turbo diesel to a Panoz roadster.

2. All of his ads have the same picture and the same price, suggesting it is the same mod for a turbo diesel or a Daewoo.

3. Not acquiring knowledge about what you are buying. A resistor that adds HP???

4. They allegedly add both HP and fuel economy. Most mods don't do both.

5. Item is shipping from overseas.